1. Field of the Invention
This invention relates to a seatbelt system for restraining and protecting an occupant in an emergency of a vehicle such as a collision, and particularly to a seatbelt system capable of automatically fastening a restraining webbing to the occupant.
2. Description of the Prior Art
Heretofore, there have been proposed seatbelt systems for automatically fastening the seatbelt system to the occupant after he is seated so as to reliably protect the occupant in an emergency of the vehicle.
In the seatbelt system as described above in FIG. 1 and in U.S. Pat. No. 4,252,342 filed on Mar. 8, 1979, one end of an inner webbing 10 is wound up by a biasing force into a retractor 12 provided at the substantially central portion of the vehicle, and a through-ring 14 is secured to the other end of the inner webbing 10. Said retractor 12 is one end of an inner webbing 10 is wound up by a biasing force into a retractor 12 provided at the substantially central portion of the vehicle, and a through-ring 14 is secured to the other end of the inner webbing 10. Said retractor 12 is a so-called emergency locking retractor for suddenly interrupting the wind-off rotation of the webbing only in an emergency of the vehicle.
One end of an outer webbing 16 is secured to a portion adjacent the upper end of a door 18 through a buckle device 20, the other end thereof is secured to a portion adjacent the lower end of the door 18 through an anchor device 22, and the intermediate portion thereof is turned back at said through-ring 14.
With the seatbelt system as arranged above, when the occupant opens the door 18 for entering the vehicle, the inner webbing 10 is wound off by a required length from the retractor 12 and a sufficient space for allowing the occupant to enter the vehicle between the inner webbing 10 and an occupant's seat 24. Consequently, when the occupant closes the door 18 upon being seated at the seat 24, the inner webbing is wound up by a wind-up force of the retractor 12, whereby the outer webbing 16 turned back at the through-ring 14 is automatically fastened to the shoulder and waist of the occupant, respectively.
Description will hereunder be given of the restraining condition of the seatbelt system with the above arrangement at the time of collision of the vehicle with referenece to FIGS. 2A through 2C. FIG. 2A shows the normal running condition of the vehicle. If the vehicle falls into a collision from the condition as described above, then the retractor 12 instantaneously interrupts the wind-off rotation of the webbing 10, and the occupant moves forward in parallel with the movement of the vehicle by a value of clearances between the webbing 10 and himself and between the webbing 16 and himself by an inertial force of collision as shown in FIG. 2B. Subsequently, the head of the occupant 26 moves forward in the vehicle, rotating on the waist of the occupant 26. This rotating movement is a phenomenon resulted from the fact that the outer webbing 16 moves through the through-ring 14 in the direction of the buckle device 20, i.e. the direction of the restrained shoulder of the occupant. It follows that the head of the occupant may dash against a steering wheel 28 and the like, thus causing injuries to the occupant.